Voyage of the Devilfish

ESM MAST An antenna that is raised to allow detailed analysis of enemy radar or radio signals. Supplements the equipment installed on the periscope.

ESM (ELECTRONICS SURVEILLANCE MEASURES) The gathering of intelligence through the analysis of enemy signals, including radars and radio transmitters.

EVAPORATOR Device that evaporates seawater using steam heat. The vapors are condensed and used as potable (drinking) water or steam plant/reactor plant makeup water. The plant comes first.

EWS (ENGINEERING WATCH SUPERVISOR) A Chief who is a roving supervisory watchstander in the engineering spaces. Reports to EOOW.

EXPLOSIVE BOLTS A hollow fastener with an explosive charge inside for quick disconnection. Used in rocket motor stages and escape pod latches.

EXTERNAL–COMBUSTION ENGINE Engine in which the fuel and oxygen bum in a chamber remote from where the work is done. Examples include jet engines and oil-burning steam plants. As opposed to internal combustion engines where the fuel is burned where the mechanical work takes place, as in an automobile engine.

FAIRWATER PLANES Winglike surfaces protruding from the sail of a submarine, used for depth control. Can be rotated to a vertical position for breaking through polar ice.

FAMILYGRAM Short three line personal radio message from a crewmember’s family, transmitted by COMSUBLANT when a ship is on a deployment. Family typically gets one message every six weeks.

FAST ATTACK SUBMARINE An SSN, a submarine designed to be small, light, quiet, fast, and lethal. Carries torpedoes to sink surface ships and other submarines. Carries cruise missiles for anti-ship warfare and for land attack. Used also as a coven intelligence gathering platform. Can put covert troops ashore using the escape trunks. Capable of months of submerged, undetected operations.

FAST LEAK A rather nasty leak from the primary coolant system of a nuclear reactor. If not isolated, will empty the water from the core and lead to a meltdown, and possibly to a prompt critical rapid disassembly.

FAST NEUTRONS Neutrons emitted by uranium nuclei undergoing fission. Mostly useless for causing another fission reaction since they want to leak from the core. Water (moderator) slows the fast neutrons down through collisions with water molecules. The slow (thermal) neutrons can then be accepted by a uranium nucleus to cause another fission. Under some conditions, uranium can be critical on fast neutrons. One example is a bomb undergoing a nuclear explosion. A second is a core in a reactivity accident such as a control rod jump, where the core becomes prompt crit’cal, critical on the fast neutrons that are emitted “promptly” by the fission reaction.

FAST RECOVERY STARTUP Emergency procedure to recover from a reactor scram at sea, using a 5 decade per minute startup rate and abbreviated turbine warmups. One of the compromises between ship safety (requiring the reactor be up for propulsion) and reactor safety (requiring a scram if there is the slightest reactor fault).

FATHOM Unit of depth equal to six feet.

FATHOMETER Bottom sounding sonar that directs an active sonar pulse down to the ocean bottom and measures the time for the pulse to reflect back and hence the distance to the bottom. New units transmit a secure pulse, using a short duration random high frequency pulse.

FBM Fleet ballistic missile submarine. Official name of a boomer.

FINAL BEARING AND SHOOT Order of the captain to shoot a torpedo after he takes one last periscope observation of a surface target.

FIRECONTROL SOLUTION A contact’s range, course, and speed. A great mystery when using passive sonar. Determining the solution requires maneuvering own ship and doing calculations on the target’s bearing rate. Can be obtained manually or with the firecontrol computer.

FIRECONTROL SYSTEM A computer system that accepts input from the periscope, sonar, and radar (when on the surface) to determine the firecontrol solution. The system also programs, fires, steers, and monitors torpedoes. If a ship is cruise missile equipped, the system will program and fire the missile.

FIRECONTROL TEAM A collection of people whose task is to put a weapon on a target. Includes the sonar operators, OOD, JOOD, Captain, XO, firecontrol operators on Pos Two, Pos Three, the firing panel, and the manual plotters (geographic, time-bearing time-range, and time-frequency).

FIRING PANEL A console section between Pos Two and Pos Three. The vertical section is a tube/weapon status panel. The horizontal section has the trigger, a lever used to fire a torpedo or cruise missile.

FIRING POINT PROCEDURES An order by the captain to the firecontrol team to tell them to prepare to fire the weapon, done during a deliberate approach when the solution is refined, as opposed to a Snapshot. The solution is locked into the weapon and the ship is put into a firing attitude.

FIRSTIE A first class midshipman at Annapolis. A senior.